Hypocalcaemia as a prognostic factor of early mortality in moderate and severe traumatic brain injury

Preoperative Serum Calcium Level Predicts Postoperative Mortality in Older Adult Patients with Hip Fracture: A Prospective Cohort Study of 2333 Patients

OBJECTIVES

Hip fractures are a significant cause of mortality among older adults. However, predictive markers for an unfavorable prognosis are still lacking. Serum calcium is an essential element in several biochemical reactions in the body. This study investigated the role of the preoperative serum calcium level as a prognostic parameter for postoperative mortality in older adult patients with hip fractures.

DESIGN

We conducted a prospective cohort study at the trauma center in our hospital, from January 1, 2015, to September 30, 2019. A total of 2333 older patients with hip fractures were recruited. This prospective cohort study was conducted in accordance with the criteria of STROCSS.

SETTING AND PARTICIPANTS

Older adult patients with hip fractures were screened between January 2015 and September 2019 at the trauma center of our hospital.

METHODS

Demographic and clinical characteristics of the patients were collected. Linear and nonlinear multivariate Cox regression models were used to identify the association between preoperative serum calcium level and all-cause mortality. All analyses were performed using EmpowerStats and the R software.

RESULTS

A total of 2333 older adult patients with hip fractures were included in the study. The mean follow-up was 37.5 months. Overall, 770 patients (33%) died of all causes. The preoperative serum calcium concentrations were 2.18 ± 0.13 mmol/L. Linear multivariate Cox regression models showed that preoperative serum calcium levels were associated with mortality [hazard ratio (HR) 0.37, 95% CI 0.21-0.67; P = .0009] after adjusting for confounders. However, the linear association was unstable, and nonlinearity was identified. A preoperative serum calcium level of 2.3 mmol/L was an inflection point for prediction. When the preoperative serum calcium concentration was below 2.3 mmol/L, serum calcium concentration increased by 1 mmol/L, and mortality risk decreased by 77% (HR 0.23, 95% CI 0.13-0.43, P < .0001). In contrast, when the preoperative serum calcium concentration was more significant than 2.3 mmol/L, the mortality risk increased with serum calcium concentration (HR 6.27, 95% CI 1.65-23.74, P = .0069).

CONCLUSIONS AND IMPLICATIONS

The preoperative serum calcium level is nonlinearly associated with mortality in older adults with hip fractures, with a U-shaped association, and could be used as a potential predictor of prognosis.

A Review of Electrolyte, Mineral, and Vitamin Changes After Traumatic Brain Injury

INTRODUCTION

Despite the prevalence of traumatic brain injury (TBI) in both civilian and military populations, the management guidelines developed by the Joint Trauma System involve minimal recommendations for electrolyte physiology optimization during the acute phase of TBI recovery. This narrative review aims to assess the current state of the science for electrolyte and mineral derangements found after TBI.

MATERIALS AND METHODS

We used Google Scholar and PubMed to identify literature on electrolyte derangements caused by TBI and supplements that may mitigate secondary injuries after TBI between 1991 and 2022.

RESULTS

We screened 94 sources, of which 26 met all inclusion criteria. Most were retrospective studies (n = 9), followed by clinical trials (n = 7), observational studies (n = 7), and case reports (n = 2). Of those, 29% covered the use of some type of supplement to support recovery after TBI, 28% covered electrolyte or mineral derangements after TBI, 16% covered the mechanisms of secondary injury after TBI and how they are related to mineral and electrolyte derangements, 14% covered current management of TBI, and 13% covered the potential toxic effects of the supplements during TBI recovery.

CONCLUSIONS

Knowledge of mechanisms and subsequent derangements of electrolyte, mineral, and vitamin physiology after TBI remains incomplete. Sodium and potassium tended to be the most well-studied derangements after TBI. Overall, data involving human subjects were limited and mostly involved observational studies. The data on vitamin and mineral effects were limited, and targeted research is needed before further recommendations can be made. Data on electrolyte derangements were stronger, but interventional studies are needed to assess causation.

Association Between Admission Ionized Calcium Level and Neurological Outcome of Patients with Isolated Severe Traumatic Brain Injury: A Retrospective Cohort Study

BACKGROUND

Traumatic brain injury (TBI) is a leading cause of death and disability worldwide. Pathophysiological processes following initial insult are complex and not fully understood. Ionized calcium (Ca++) is an essential cofactor in the coagulation cascade and platelet aggregation, and hypocalcemia may contribute to the progression of intracranial bleeding. On the other hand, Ca++ is an important mediator of cell damage after TBI and cellular hypocalcemia may have a neuroprotective effect after brain injury. We hypothesized that early hypocalcemia might have an adverse effect on the neurological outcome of patients suffering from isolated severe TBI. In this study, we aimed to evaluate the relationship between admission Ca++ level and the neurological outcome of these patients.

METHODS

This was a retrospective, single-center, cohort study of all patients admitted between January 2014 and December 2020 due to isolated severe TBI, which was defined as head abbreviated injury score ≥ 4 and an absence of severe (abbreviated injury score > 2) extracranial injuries. The primary outcome was a favorable neurological status at discharge, defined by a modified Rankin Scale of 0-2. Multivariable logistic regression was performed to determine whether admission hypocalcemia (Ca++  < 1.16 mmol L-1) is an independent predictor of neurological status at discharge.

RESULTS

The final analysis included 201 patients. Hypocalcemia was common among patients with isolated severe TBI (73.1%). Most of the patients had mild hypocalcemia (1 < Ca++  < 1.16 mmol L-1), and only 13 (6.5%) patients had Ca++  ≤ 1.00 mmol L-1. In the entire cohort, hypocalcemia was independently associated with higher rates of good neurological status at discharge (adjusted odds ratio of 3.03, 95% confidence interval 1.11-8.33, p = 0.03). In the subgroup of 81 patients with an admission Glasgow Coma Scale > 8, 52 (64.2%) had hypocalcemia. Good neurological status at discharge was recorded in 28 (53.8%) of hypocalcemic patients compared with 14 (17.2%) of those with normal Ca++ (p = 0.002). In multivariate analyses, hypocalcemia was independently associated with good neurological status at discharge (adjusted odds ratio of 6.67, 95% confidence interval 1.39-33.33, p = 0.02).

CONCLUSIONS

Our study demonstrates that among patients with isolated severe TBI, mild admission hypocalcemia is associated with better neurological status at hospital discharge. The prognostic value of Ca++ may be greater among patients with admission Glasgow Coma Scale > 8. Trials are needed to investigate the role of hypocalcemia in brain injury.

Cellular and Molecular Pathophysiology of Traumatic Brain Injury: What Have We Learned So Far?

Traumatic brain injury (TBI) is one of the leading causes of long-lasting morbidity and mortality worldwide, being a devastating condition related to the impairment of the nervous system after an external traumatic event resulting in transitory or permanent functional disability, with a significant burden to the healthcare system. Harmful events underlying TBI can be classified into two sequential stages, primary and secondary, which are both associated with breakdown of the tissue homeostasis due to impairment of the blood-brain barrier, osmotic imbalance, inflammatory processes, oxidative stress, excitotoxicity, and apoptotic cell death, ultimately resulting in a loss of tissue functionality. The present study provides an updated review concerning the roles of brain edema, inflammation, excitotoxicity, and oxidative stress on brain changes resulting from a TBI. The proper characterization of the phenomena resulting from TBI can contribute to the improvement of care, rehabilitation and quality of life of the affected people.

Traumatic Brain Injury, Electrolyte Levels, and Associated Outcomes: A Systematic Review

INTRODUCTION

Although it has been established that electrolyte abnormalities are a consequence of traumatic brain injury (TBI), the degree to which electrolyte imbalances impact patient outcomes has not been fully established. We aim to determine the impact of sodium, potassium, calcium, and magnesium abnormalities on outcomes in patients with TBI.

METHODS

Four databases were searched for studies related to the impact of electrolyte abnormalities on outcomes for TBI patients. Outcomes of interest were rates of mortality, Glasgow Outcome Scale (GOS), and intensive care unit length of stay (ICU-LOS). The search included studies published up to July 21, 2022. Articles were then screened and included if they met inclusion and exclusion criteria.

RESULTS

In total, fourteen studies met inclusion and exclusion criteria for analysis in this systematic review. In patients with TBI, an increased mortality rate was associated with hypernatremia, hypokalemia, and hypocalcemia in the majority of studies. Both hyponatremia and hypomagnesemia were associated with worse GOS at 6 months. Whereas, both hyponatremia and hypernatremia were associated with increased ICU-LOS. There was no evidence to suggest other electrolyte imbalances were associated with either GOS or ICU-LOS.

CONCLUSIONS

Hyponatremia and hypomagnesemia were associated with worse GOS. Hypernatremia was associated with increased mortality and ICU-LOS. Hypokalemia and hypocalcemia were associated with increased mortality. Given these findings, future practice guidelines should consider the effects of electrolytes' abnormalities on outcomes in TBI patients prior to establishing management strategies.

Initial Serum Levels of Magnesium and Calcium as Predictors of Mortality in Traumatic Brain Injury Patients: A Retrospective Study

Background: We sought to evaluate the predictor role of the initial serum level of calcium and magnesium in hospitalized traumatic brain injury (TBI) patients. Materials and methods: A retrospective analysis of all TBI patients admitted to the Hamad Trauma Center (HTC), between June 2016 and May 2021 was conducted. Initial serum electrolyte levels of TBI patients were obtained. A comparative analysis of clinical variables between patients with abnormal and normal serum electrolyte level was performed. Logistic regression analysis with the variables that showed a significant difference (p < 0.05) in the bivariate analysis was performed to calculate the odds ratios (OR) for mortality. Results: There was a total of 922 patients with clinical records of serum electrolyte levels at admission. Of these, 757 (82.1%) had hypocalcemia, 158 (17.1%) had normal calcium level, and 7 (0.8%) had hypercalcemia. On the other hand, 616 (66.8%) patients had normal magnesium level, 285 (30.9%) had hypomagnesemia, and 12 (1.3%) had hypermagnesemia. The mortality rate in hypocalcemia group was 24% while in patients with normal calcium level it was 12%, p = 0.001. Proportionate mortality rates in hypomagnesemia and normal magnesium groups were 15% and 23% (p = 0.006), respectively. On the other hand, 7 out of 12 (58%) hypermagnesemia patients died during the index hospitalization. The regression model including GCS, ISS, PT, aPTT, INR, Hemoglobin, Bicarbonate, Lactate, Sodium, Potassium, Calcium, Magnesium, and Phosphate showed that hypocalcemia was not a significant predictor [OR 0.59 (CI 95%: 0.20–1.35)] of mortality after TBI. However, hypermagnesemia was a significant predictor [OR 16 (CI 95%: 2.1–111)] in addition to the GCS, ISS, aPTT, Bicarbonate, and Lactate values on admission. Conclusion: Although hypocalcemia and hypomagnesemia are common in hospitalized TBI patients, hypocalcemia was not a significant predictor of mortality, while hypermagnesemia was an independent predictor. Further studies with larger sample size and with prospective design are required to support these findings and their importance.

Association of hypocalcemia with in-hospital mortality in critically ill patients with intracerebral hemorrhage: A retrospective cohort study

Background and purpose

There was little evidence to study the relationship between hypocalcemia and mortality among critically ill patients with intracerebral hemorrhage (ICH) aged ≥16 years. This study aimed to determine the potential association between hypocalcemia and in-hospital and ICU mortality in patients with ICH in the United States.

Methods

We analyzed 1,954 patients with ICH from the e-Intensive Care Unit Collaborative Research Database and divided them into hypocalcemia and non-hypocalcemia groups. Hypocalcemia was defined as albumin-adjusted total calcium below 8.4 mg/dl. The primary and secondary outcomes were hospital and ICU mortality, respectively. We performed multivariable regression and subgroup analyses to evaluate the association of hypocalcemia with hospital and ICU mortality. Cumulative survival rate analysis was performed using Kaplan-Meier curves with log-rank statistics.

Results

We enrolled 1,954 patients with ICH who had been hospitalized in ICU for >24 h and were older than 16 years (average age, 61.8 years; men, 56.7%). We noted that 373 (19%) hospital mortality occurred, including 235 (12%) ICU mortality. In this sample, 195 patients had hypocalcemia. Multivariable logistic regression analyses showed that hypocalcemia was associated with a 67% increased risk of in-hospital and a 72% increased risk of ICU mortality. This association was consistent across subgroup analyses.

Conclusions

Hypocalcemia was associated with a high risk of hospital and ICU mortality among critically ill patients with ICH. Future prospective, randomized, controlled studies are needed to confirm our results.

Admission Serum Ionized and Total Calcium as New Predictors of Mortality in Patients with Cardiogenic Shock

Background

Although serum calcium has been proven to be a predictor of mortality in a wide range of diseases, its prognostic value in critically ill patients with cardiogenic shock (CS) remains unknown. This retrospective observational study is aimed at investigating the association of admission calcium with mortality among CS patients.

Methods

Critically ill patients diagnosed with CS in the Medical Information Mart for Intensive Care-III (MIMIC-III) database were included in our study. The study endpoints included 30-day, 90-day, and 365-day all-cause mortalities. First, admission serum ionized calcium (iCa) and total calcium (tCa) levels were analyzed as continuous variables using restricted cubic spline Cox regression models to evaluate the possible nonlinear relationship between serum calcium and mortality. Second, patients with CS were assigned to four groups according to the quartiles (Q1-Q4) of serum iCa and tCa levels, respectively. In addition, multivariable Cox regression analyses were used to assess the independent association of the quartiles of iCa and tCa with clinical outcomes.

Results

A total of 921 patients hospitalized with CS were enrolled in this study. A nonlinear relationship between serum calcium levels and 30-day mortality was observed (all P values for nonlinear trend < 0.001). Furthermore, multivariable Cox analysis showed that compared with the reference quartile (Q3: 1.11 ≤ iCa < 1.17 mmol/L), the lowest serum iCa level quartile (Q1: iCa < 1.04 mmol/L) was independently associated with an increased risk of 30-day mortality (Q1 vs. Q3: HR 1.35, 95% CI 1.00-1.83, P = 0.049), 90-day mortality (Q1 vs. Q3: HR 1.36, 95% CI 1.03-1.80, P = 0.030), and 365-day mortality (Q1 vs. Q3: HR 1.28, 95% CI 1.01-1.67, P = 0.046) in patients with CS.

Conclusions

Lower serum iCa levels on admission were potential predictors of an increased risk of mortality in critically ill patients with CS.

Association Between Ionized Calcium Level and Neurological Outcome in Endovascularly Treated Patients with Spontaneous Subarachnoid Hemorrhage: A Retrospective Cohort Study

BACKGROUND

Spontaneous subarachnoid hemorrhage (SSAH) is associated with significant morbidity and mortality. Pathophysiological processes following initial bleeding are complex and not fully understood. In this study, we aimed to determine whether a low level of ionized calcium (Ca⁺⁺), an essential cofactor in the coagulation cascade and other cellular processes, is associated with adverse neurological outcome, development of early hydrocephalus, and symptomatic vasospasm among patients with SSAH.

METHODS

This was a retrospective single-center cohort study of all patients admitted for SSAH between January 1, 2009, and April 31, 2020. The primary outcome was an unfavorable neurological status at discharge, defined as a modified Rankin Scale score greater than or equal to 3. Secondary outcomes were the development of early hydrocephalus and symptomatic vasospasm. Multivariable logistic regression was performed to determine whether Ca⁺⁺ was an independent predictor of these outcomes.

RESULTS

A total of 255 patients were included in the final analysis. Hypocalcemia, older age, admission Glasgow Coma Scale (GCS) score, and admission Hunt-Hess classification scale (H&H) grades IV and V were independently associated with unfavorable neurological outcome, with adjusted odds ratios (ORs) of 1.93 (95% confidence interval [CI] 1.1-3.4; p = 0.02) for each 0.1 mmol L^-1 decrease in the Ca⁺⁺ level, 1.04 (95% CI 1.01-1.08; p = 0.02) for each year increase, 0.82 (95% CI 0.68-0.99; p = 0.04), and 6.29 (95% CI 1.14-34.6; p = 0.03), respectively. Risk factors for the development of hydrocephalus were hypocalcemia and GCS score, with ORs of 1.85 (95% CI 1.26-2.71; p = 0.002) for each 0.1 mmol L^-1 decrease in the Ca⁺⁺ level and 0.83 (95% CI 0.73-0.94; p = 0.005), respectively. Ca⁺⁺ was not associated with symptomatic vasospasm (OR 1.04 [95% CI 0.76-1.41]; p = 0.81). Among patients with admission H&H grade I-III bleeding, hypocalcemia was independently associated with unfavorable neurological outcome at discharge, with an adjusted OR of 1.99 (95% CI 1.03-3.84; p = 0.04) for each 0.1 mmol L^-1 decrease in the Ca⁺⁺ level. Hypocalcemia was also an independent risk factor for the development of early hydrocephalus, with an adjusted OR of 2.95 (95% CI 1.49-5.84; p = 0.002) for each 0.1 mmol L^-1 decrease in the Ca⁺⁺ level. Ca⁺⁺ was not associated with symptomatic vasospasm. No association was found between Ca⁺⁺ and predefined outcomes among patients with admission H&H grade IV and V bleeding.

CONCLUSIONS

Our study shows that hypocalcemia is associated with worse neurological outcome at discharge and development of early hydrocephalus in endovascularly treated patients with SSAH. Potential mechanisms include calcium-induced coagulopathy and higher blood pressure. Trials are needed to assess whether correction of hypocalcemia will lead to improved outcomes.

Hypocalcemia in trauma patients: A systematic review

BACKGROUND

During hemorrhagic shock and subsequent resuscitation, pathways reliant upon calcium such as platelet function, intrinsic and extrinsic hemostasis, and cardiac contractility are disrupted. The objective of this systematic review was to examine current literature for associations between pretransfusion, admission ionized hypocalcemia, and composite outcomes including mortality, blood transfusion requirements, and coagulopathy in adult trauma patients.

METHODS

This review was reported using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist. We searched Ovid MEDLINE and grey literature from database inception till May 3, 2020. Case series and reports were excluded. Reference lists of appraised studies were also screened for articles that the aforementioned databases might not have captured. The Newcastle-Ottawa Scale was used to assess study quality.

RESULTS

A total of 585 abstracts were screened through database searching and alternative sources. Six unique full-text studies were reviewed, of which three were excluded. Admission ionized hypocalcemia was present in up to 56.2% of the population in studies included in this review. Admission ionized hypocalcemia was also associated with increased mortality in all three studies, with increased blood transfusion requirements in two studies, and with coagulopathy in one study.

CONCLUSION

Hypocalcemia is a common finding in shocked trauma patients. While an association between admission ionized hypocalcemia and mortality, blood transfusion requirements, and coagulopathy has been identified, further prospective trials are essential to corroborating this association.

LEVEL OF EVIDENCE

Systematic review, level III.

Impact of admission serum calcium levels on mortality in hospitalized patients

OBJECTIVES

To assess the relationship between admission serum calcium levels and in-hospital mortality in all hospitalized patients.

METHODS

All adult hospitalized patients who had admission serum calcium levels available between years 2009 and 2013 were enrolled. Admission serum calcium was categorized based on its distribution into six groups (<7.9, 7.9 to <8.4, 8.4 to <9.0, 9.0 to <9.6, 9.6 to <10.1, and ≥10.1 mg/dL). The odds ratio (OR) of in-hospital mortality by admission serum calcium, using the calcium category of 9.6-10.1 mg/dL as the reference group, was obtained by logistic regression analysis.

RESULTS

18,437 patients were studied. The lowest incidence of in-hospital mortality was associated with admission serum calcium within 9.6 to <10.1 mg/dL. A higher in-hospital mortality rate was observed in patients with serum calcium <9.6 and ≥10.1 mg/dL. Also, 38% and 33% of patients with admission serum calcium <7.9 and ≥10.1 mg/dL were on calcium supplements before admission, respectively. After adjusting for potential confounders, both serum calcium <8.4 and ≥10.1 mg/dL were associated with an increased risk of in-hospital mortality with ORs of 2.86 [95% confidence interval (CI) 1.98-4.17], 1.74 (95% CI 1.21-2.53), and 1.69 (95% CI 1.10-2.59) when serum calcium were within <7.9, 7.9 to <8.4, and ≥10.1 mg/dL, respectively.

CONCLUSION

Hypocalcemia and hypercalcemia on admission were associated with in-hospital mortality. Highest mortality risk is observed in patients with admission hypocalcemia (<7.9 mg/dL). One-third of patients with hypercalcemia on admission were on calcium supplements.

Hypocalcemia as a prognostic factor in mortality and morbidity in moderate and severe traumatic brain injury

Objectives:

Our main objective was to evaluate whether serum hypocalcaemia (defined as <2.1 mmol/L [8.5 mg/dL]) and ionized serum calcium (defined as <1.10 mmol/L [4.5 mg/dL]) is a prognostic factor for mortality and morbidity (defined as Glasgow outcome score [GOS] ≤3) in early moderate and severe traumatic brain injury (TBI).

Materials and Methods:

We developed a retrospective study and evaluated clinical profiles from included patients from January 2004 to December 2012. Patients were between 16 and 87 years old and had a Glasgow coma scale of 3–13 points following TBI, with demonstrable intracranial lesions in cranial computed tomography.

Results:

We found a significant statistical difference (P < 0.008) in the ionized serum calcium levels on the 3^rd day of admission between the groups: GOS ≤3 and >3 (disability/death). According with the receiving operative curves analysis, we found that the best level of higher sensitivity (83.76%) and specificity (66.66%) of hypocalcaemia of serum ionized calcium on 3^rd day was the value of 1.11 mmol/L, with an odds ratio value of 6.45 (confidence intervals 95%: 2.02–20.55).

Conclusions:

The serum levels of ionized calcium on day 3 could be useful for the prediction of mortality and disability in patients with moderate and severe TBI.

Calcium Disorders in the Emergency Department: Independent Risk Factors for Mortality

Background

Calcium disorders are common in both intensive care units and in patients with chronic kidney disease and are associated with increased morbidity and mortality. It is unknown whether calcium abnormalities in unselected emergency department admissions have an impact on in-hospital mortality.

Methods

This cross-sectional analysis included all admissions to the Emergency Department at the Inselspital Bern, Switzerland from 2010 to 2011. For hyper- and hypocalcaemic patients with a Mann-Whitney U-test, the differences between subgroups divided by age, length of hospital stay, creatinine, sodium, chloride, phosphate, potassium and magnesium were compared. Associations between calcium disorders and 28-day in-hospital mortality were assessed using the Cox proportional hazard regression model.

Results

8,270 patients with calcium measurements were included in our study. Overall 264 (3.2%) patients died. 150 patients (6.13%) with hypocalcaemia and 7 patients with hypercalcaemia (6.19%) died, in contrast to 104 normocalcaemic patients (1.82%). In univariate analysis, calcium serum levels were associated with sex, mortality and pre-existing diuretic therapy (all p<0.05). In multivariate Cox regression analysis, hypocalcaemia and hypercalcaemia were independent risk factors for mortality (HR 2.00 and HR 1.88, respectively; both p<0.01).

Conclusion

Both hypocalcaemia and hypercalcaemia are associated with increased 28-day in-hospital mortality in unselected emergency department admissions.